오류는 다음에 수학을하고 결과를 보여

Question

여기

코드이지만, 내가 응용 프로그램을 시작할 때 그것은 안드로이드 모니터 결과를

public class Main2Activity extends AppCompatActivity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main2); 
    ImageButton imageButton = (ImageButton) findViewById(R.id.imageButton); 
    ImageButton imageButton2 = (ImageButton) findViewById(R.id.imageButton2); 
    ImageButton imageButton3= (ImageButton) findViewById(R.id.imageButton3); 
    ImageButton imageButton4 = (ImageButton) findViewById(R.id.imageButton4); 
    ImageButton imageButton5 = (ImageButton) findViewById(R.id.imageButton5); 
    ImageButton imageButton6 = (ImageButton) findViewById(R.id.imageButton6); 
    ImageButton imageButton7 = (ImageButton) findViewById(R.id.imageButton7); 
    ImageButton imageButton8 = (ImageButton) findViewById(R.id.imageButton8); 
    ImageButton imageButton9 = (ImageButton) findViewById(R.id.imageButton9); 
    final EditText editText = (EditText) findViewById(R.id.editText); 
    EditText editText2 = (EditText) findViewById(R.id.editText2); 
    EditText editText3 = (EditText) findViewById(R.id.editText3); 
    final TextView textView50 = (TextView)findViewById(R.id.textView50); 
    //here where the android monitor says it error 

    final int dayNumber = Integer.parseInt(editText.getText().toString()); 
    editText2.getText(); 
    editText3.getText(); 
    imageButton3.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
     int a = dayNumber * 4; 
      textView50.setText(String.valueOf(a)); 
     } 
    }); 

충돌하고 여기

E/AndroidRuntime: FATAL EXCEPTION: main 
Process: ahmednageeb.com.yourageinotherplanets, PID: 19858 
java.lang.RuntimeException: Unable to start activity ComponentInfo{ahmednageeb.com.package/ahmednageeb.com.package.Main2Activity}: java.lang.NumberFormatException: Invalid int: "" 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
    at android.app.ActivityThread.-wrap11(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:148) 
    at android.app.ActivityThread.main(ActivityThread.java:5417) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
Caused by: java.lang.NumberFormatException: Invalid int: "" 
    at java.lang.Integer.invalidInt(Integer.java:138) 
    at java.lang.Integer.parseInt(Integer.java:358) 
    at java.lang.Integer.parseInt(Integer.java:334) 
    at ahmednageeb.com.package.Main2Activity.onCreate(Main2Activity.java:40) 
    at android.app.Activity.performCreate(Activity.java:6237) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)  
    at android.app.ActivityThread.-wrap11(ActivityThread.java)  
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)  
    at android.os.Handler.dispatchMessage(Handler.java:102)  
    at android.os.Looper.loop(Looper.java:148)  
    at android.app.ActivityThread.main(ActivityThread.java:5417)  
    at java.lang.reflect.Method.invoke(Native Method)  
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)  
07-31 19:45:56.587 19858-19858/ahmednageeb.com.package I/Process: Sending signal. PID: 19858 SIG: 9 

Answer 1

보기가로드 될 때가 아니라 실제로 단추를 클릭하면 EditText를 구문 분석하십시오.

imageButton3.setOnClickListener(new View.OnClickListener() { 
    @Override 
    public void onClick(View view) { 
     int dayNumber = 0; 
     String s = editText.getText().toString(); 
     if (!s.isEmpty()) { 
      dayNumber = Integer.parseInt(s); 
     } 

     // Unused variables, but actually get the value if needed 
     String s2 = editText2.getText().toString(); 
     String s3 = editText3.getText().toString(); 

     int a = dayNumber * 4; 
     textView50.setText(String.valueOf(a)); 
    } 
});